In a conventional bag having a bag body constituted by placing two laminated films formed by laminating together several layers of synthetic resin film over each other and heat-sealing the peripheral edges thereof, when part of the bag body is opened in order to remove the contents, since the bag body is constituted by laminated films, the bag body is difficult to tear and hence the opening is difficult.
For resolving the above defects of the conventional bags, the inventor of the present invention has devised an easy-to-open synthetic resin bag comprising: a bag body constituted by a laminated film formed by laminating synthetic resin films; a tear string bonded to part of the inner surface of the bag body corresponding to the tear line thereof; and a tab formed over an end of the tear string which substantially consists of a pair of parallelly-spaced-apart side notches formed on both sides of the tear string and a transverse groove which is disposed adjacent to the side notches with a suitable space and extends perpendicular to the tear string and has a width far greater than the space between the side notches, whereby pulling the tear string by the tab enables the side surface to which the tear string is bonded to be easily and surely torn, thereby allowing the bag body to be easily and speedily opened.
It is an object of the present invention to provide a bag-manufacturing apparatus capable of continuously and readily manufacturing the above easy-to-open synthetic resin bags in an inexpensive manner.